写了个SQL语句，发到这里留念

刚好这两天在培训SQL server 练习了一下~~

我这里有个成绩表（学号，课程代号，成绩字段）和学生表（姓名，学号，班级字段）要求查询出每个学生的总成绩
这样写那里有错！？？？
select  学号,姓名,sum(成绩) as [总成绩] from 学生表,成绩表 where 班级=bj2 and 学生表.学号=成绩表.学号 order by 总成绩 desc

提供正解
use ***
select 学生表.学号 as TID,学生表.学号 as TNAME,sum(成绩表.成绩字段) as MARK
from 学生表 join 成绩表
on 成绩表.学号=学生表.学号
where 班级字段='grade2'
group by 学生表.学号,学生表.学号
order by MARK desc
go

即：
use tempdb
select T_student.S_id as TID,T_student.S_name as TIDD,sum(T_mark.Mark) as AmountSold
from T_mark join T_student
on T_mark.S_id=T_student.S_id
where S_class='grade2'
group by T_student.S_id,T_student.S_name
order by AmountSold desc
go